You can identify the positive and negative terminals on a solar panel by checking for visual markings like '+' and '-' symbols, colored wires (typically red for positive, black for negative), using a multimeter to measure voltage, and consulting the manufacturer's documentation.
Solar panel discoloration is typically the result of long-term exposure to the elements, such as sunlight, rain, and dust. This issue may affect the aesthetic appearance of the panels, but it does not generally impact their functionality or efficiency.